Coating composition.



TED STATES PATENT OFFICE.

OARLETON ELLIS AND ALFRED A. WELLS, OF MONTCLAIR, NEW JERSEY.

COATING COMPOSITION.

No Drawing.

To all whom it may concern Be it known that we, CARLETON ELLIS and Anrnno A. lYELLs, citizens of the United States, and residents of Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Coating Compositions, of which the following is a specification.

This invention relates to a composition .of matter adapted for use as a vehicle for 7 painting concrete and cement structures or divers sorts and relates particularly to a composition containing rubber resin, all as more fully hereinafter described and claimed.

Concrete made from Portland cement is ordinarily rather porous and lacking in waterproof qualities; also it has a grayish brown tint usually prepared which, for certain purposes is not desired. The cement used in the concrete contains a considerable amount of alkali in the form of free lime, or lime in loose combination; also potash or soda in basic form. In addition, bodies of a more or less water soluble nature are present and these compounds, under the action of moisture tend to migrate from the interior of the concrete mass and a wear on the surface thereof as a white etllorescence known by the artisan as saltpeter or lime stains. These are very unsightly and often greatly injure the appearance of buildings, such as dwelling houses constructed of solid or monolithic concrete and stucco. Moreover. the surface. of concrete often undergoes a slight disinte ration, known as checking, which renders the surface unsightly, so for these and other reasons, concrete surfaces frequently need to be painted.

The basis of ordinary paint, linseed oil, is not adapted for use in the painting of concrete. Linseed oil, being a readily saponifiabie oil, is affected by the alkalis of the cement and is decomposed rather rapidly. \Vith the idea of overcoming these difficulties, proposals have been made to treat the surface of the concrete, prior to painting, with an acid, or neutralizing wash, such as aqueous solutions of hydrochloric and sulfuric acids, zinc sulfate, ammonium carbonate and the like. In addition to the time required to apply such a wash, the work has to be delayed in order to permit the water to dry out before the paint is applied and the, surface of the cemcv t, because of such drastic acid treatment, is oftentimes Specification of Letters Patent.

Application filed August 13, 1912. Serial No. 714,813.

more or less disintegrated, the bonding of the cement is in a measure destroyed, especially at the surface, leading to scaling and checking. This action is enhanced by the action of frost in winter and may lead to a very great deterioration of the painted sur face. Then too, there is always danger that alkalis from the interior of the cement mass may find their way to the surface of the mass and affect the paint coating by saponifying action; for the neutralizing action of the acid wash is only superficial at best, leaving the interior of the cement with its full quota of unneutralized alkali. For this and other reasons linseed oil has not found favor in the painting of concrete.

Solutions of ordinary varnish gums, such as Manila or kauri cop-a1 in turpentine and other solvents have also been suggested, but these also are saooniliable to a very considerable degree and are open in a large measure to the same objections noted in the case of linseed oil.

()ur invention has to do'with paint vehicles which essentially are substantially free from binding materials affected by the alkalis of cement, and comprises the use of resins, or resinous materials extracted from rubber gums and in particular the rubber gum known as jelutong.

Different qualities ofjelutong are known in the trade, according to the source from which they are derived, as Palembang, (Sumatra) lontianak, (Borneo), Sarawak, and the like. Commercial jelutong is obtained by coagulating the latex derived from the jelutoug tree. Commercial jelutong 0011' tains roughly about 70% water, and 30% solid material, the latter consisting of about one-third rubber and two-thirds resin, so that for about each pound of rubber recovered, about two pounds of resin are obtained. The resin has found but few uses, and has constituted a waste, or by-product of considerable magnitude.

The process of deresination as now practised by the aid of solvents. leaves the resin in the form of a mass of white particles, or friable lumps, usually containing some moisture and the method of treatn'ient for rendering this resin suitable as a basis for concrete paint vehicles, or oils, will shortly be described.

Chute has called attention to the difiiculty of utilizing Iontianak rubber resin, (India Rubber World, July 1st, 1909) and has given some data as to the properties of this resin. His data as to the solutions of this resin coincide to a considerable extent with our own observations, except that no mention has been made by Chute of the instability of many of the solutions of resin.

When first prepared, clear solutions are readily obtained, as for example, by melting one part of Pontianak rubber resin and thinning with two parts of petroleum naphtha. Such a clear solution is however, supersaturated and on keeping for a few weeks or months or even longer, separation of the less soluble portion occurs spontaneously and the former clear solution becomes largely a grayish paste, or solid mass. Most common solvents act in this way as the following tabulation indicates: For example. a clear liquid mixture made from equal parts of lontianak resin and pine oil. on standing for a considerable period becomes solid; with one part resin and two parts pine oil, becomes about one-half filled with solid material; with one part resin and one part each of pine oil and solvent naphtha, nearly solidi Nearly solid products are pro ducedon standing by mixing two parts of lontianak resin with one part each of pine oil and heavy benzin. also two parts resin to two parts each of these solvents give like results. Light benzin, (varnish makers benz'in) with pine oil in varying proportions, acts in the same way. Equal parts of the resin and spirits of turpentine solidify as do mixtures composed of three and four parts of turpentine to two parts of resin. There is great uncertainty respecting the permanency of such solutions in storage. The solidification may occur in a few days or the solutions may retain their mobility and clarity for a long time to finally coagu late and become worthless as finish coating material. The various factors which enter into phenomena of spontaneous coagulation have not as yet been fully determined by us and we content ourselves for the present simply with calling attention to these obser vations.

In the present preparation of finish coatings, such as paint oils, varnishes and the like, concentrated solutions of resin are often required. For example, making rosin varnish known as the gloss oil type, five or six parts of ordinary rosin are used to four or five parts of benzin. \Vith Pontianak rubber resin, ordinarily such concentrations would be impossible to secure.

In the manufacture of varnish from hard resins, it is quite customary to heat such resins to a temperature of 500 to (500 de grees F. in order to render them more suitable for combination with oils, etc. But in the case of Pontianak resin, it has been supposed that a temperature of 400 degrees could not be exceeded, owing to the formation of acetic acids and other supposedly injurious bodies. We have found, however, that for the proper transformation of Pont-ianak resin into a form desirable or suit able for the pre iiaration of Pontianak oils or concrete coating vehicles, that temperatures above 600 to 700 F. are desirable. \Ve have found that by heating the Pontianak resin in a retort having a reflux con denser so'as to return to the condenser the products of distillation at temperatures at 675 to 700 degrees F. or higher, distillation takes place and the resin is converted to an acid body due to the formation of acetic acid and the like. By inserting a suitable dephlegmator the oily material may be returned to the still while the acetic and similar material is collected separately. By such differential concentration a substantially neutral resin can be secured whose physical properties depend upon the length of time of distillation. One hours distillation treatment gives a mass which firm but tacky; two hours treatment gives a very thick but fluent mass. Four hours treatment gives a liquid material of the consistency of molasses or thereabout. The latter product is readily soluble in heavy benzin in any proportion and affords a coating which is free from the objection of frosting' mentioned above. Continuous heating in this manner also accomplishes another desirable purpose in that it decreases the unsaturated portion of the resin compound, the iodin number often doubling or tripling by such distillation treatment. This enables the compounds to acquire siccative properties. especially in the presence of a drier such lead. or manganese resinate oleate or linoleate. or other suitable drying agents.

In order to secure a paint oil of the proper drying qualitie", the mass after being dis tilled with a refiux condenser may be redistilled with a goose-neck still to yield limpid paint oils having drying properties. By fractionating these oils the lower boiling fractions or spirits containing isoprene and the like may be separated from the heavier oils. The latter in turn may be separated into light, medium and heavy paint oils which may be used for various purposes other than those indicated. These paintoils have the very desirable property of low. degree of acidity, usually only traces or immaterial amounts of acid being present or the composition being entirely neutral. This is a great advantage in the manufacture of paints from basic pigments. The absence of fixed or nonvolatile acid in these oils precludes the solidification or thickening of the pigment by such undesirable reac tion as occurs in the case of ordinary resin or rancid paint oils.

A further advantage of such substantially neutral paint or paint oils is that when applied to concrete no reaction with the lime of the cement occurs after the coating has been applied and dried. In the case of concrete coatings containing acid bodies of certain type, drying takes place before reaction between the lime and acid is complete and the subsequent completion of the reaction with apparent change of volume has a tendency to cause rupturing of the paint film.

These resinous bodies contain a certain amount of saponifiable material which is very inert to the action of alkali, but difficulties may occur under certain conditions of treatment when acid bodies are formed giving the composition in acid value calculated as oleic acid of one-fourth to onehalf of one per cent. To avoid the presence of objectionable amounts of acid material, we prefer to filter the roduct through a tower containing granu ar quick lime in order that from the solution we may remove any traces of acid material capable of uniting with lime. Thus a coating material is provided which affords very permanent, tenacious coatings. In a similar manner a small amount of lime may be added to the kettle or retort while preparing the composition. Or after manufacturing, the oil may be agitated while still warm with quick lime or hydrated lime. Solutions of the resin suitable as paint vehicles may be made in the following way. 125 poundsof Pontianak resin is heated for about four hours in a still provided with a reflux air condenser for the return of the oil and having a watercooled down turning condenser connected with the reflux condenser so as to remove from the mass undergoing distillation the volatile acids as fast as they are formed. This enables a reaction in the resin conducive to increased drying properties and the like to take place with greater ease and we regard this step as an important feature of our procedure. At the end of four hours the resin is run from the retort and thinned with any suitable solvent such as benzol, benzin, turpentine. wood-tnmentine, texene which is a variety of heavy benzin, solvent naphtha. toluol and the like. A thinner such as heavy benzin which is a very poor solvent for the normal resin is capable of readily reducing the fluent material to concentrations to 50 or 60% without danger of separation of the resin. After being treated in this manner the solution if dark colored may be bleached if desired by filtration through fuller-s earth, or bone-black, or by treatment with chemical bleaching agents such as chlorin and its compounds having bleaching properties; also such bodies as sodium peroxid, ozone, and the like.

Solutions of the fluent mass may be. in-

corporated if desired with other drying oils and driers, including fish, linseed, chinawood, corn and so *a bean oils. Ten to twenty per cent. of (lhina wood oil added to the limpid oils obtained by rectification of the distilled resin form a very useful composile paint oil. The treatment of the resin at these high temperatures may take place if desired at reduced atmospheric pressures. The temperature and length of. heat treatment under such circumstances depend upon the amount of .reduction of atmospheric pressure prevailing.

The solution may be thickened if desired with various colloidal or other thickeners, including such compounds as aluminum and lime soaps of fish oil, wood oil and the like, or the corresponding oleates and linoleates. Rubber also may be introduced as a thick ening agent and wax such as ceresin, or beeswax may be employed especially to afford a flat drying composition.

It should be understood that we do not wish to limit ourselves to the precise ingredients described in the foregoing but may invoke the doctrine of equivalency as far as the same may be herein applicable. For example, additions of saponifiaole resins, such. as kauri copal may be made to a greater or less extent depending upon the age of the concrete and on the mass or relative proportion of unsaponifiable resin present. A large amount of Pontianak resin may embed, as it were, a small amount of colophony or kauri and thus for a Ion time protect these more susceptible bodies from the action of alkali.

\Vhat we claim is:

1. As an oily product a fluent resin comprising substantially unsaponifiable not volatile liquid rubber resin.

:3. As a new product an oil of rubber resin having somewhat siccative )roperties.

3. As a new roduct an oil of ontianak rubber resin of a substantially unsaponifiable character.

4. As a new product the oil of Pontianak rubber resin.

Signed at Montclair, in the county of Essex and State of New Jersey, this 8th day of August, A. D. 1912.

CARLETON ELLIS. A. A. WEIJIJS.

lVitnesses:

I. DAVID LUBETZKI, A. H. NEY. 

